/**
 * MyFilterSecurityInterceptor.java
 * 2012-10-23
 * liqing
 */
package com.gzceb.zhgjj.security;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

import org.springframework.security.access.SecurityMetadataSource;
import org.springframework.security.access.intercept.AbstractSecurityInterceptor;
import org.springframework.security.access.intercept.InterceptorStatusToken;
import org.springframework.security.web.FilterInvocation;
import org.springframework.security.web.access.intercept.FilterInvocationSecurityMetadataSource;

/**
 * <p>
 * 生成securityMetadataSource。
 * </p>
 * 
 * @date 2012-10-23上午9:53:59
 * @author user
 * @description 该过滤器的主要作用就是通过spring著名的IoC生成securityMetadataSource。
 *              securityMetadataSource相当于本包中自定义的MyInvocationSecurityMetadataSourceService
 *              。
 *              该MyInvocationSecurityMetadataSourceService的作用提从数据库提取权限和资源，装配到HashMap中
 *              ， 供Spring Security使用，用于权限校验。
 */
public class MyFilterSecurityInterceptor extends AbstractSecurityInterceptor
		implements Filter {

	private FilterInvocationSecurityMetadataSource securityMetadataSource;

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {

		FilterInvocation fi = new FilterInvocation(request, response, chain);
		invoke(fi);

	}

	public FilterInvocationSecurityMetadataSource getSecurityMetadataSource() {
		return this.securityMetadataSource;
	}

	public void invoke(FilterInvocation fi) throws IOException,
			ServletException {

		InterceptorStatusToken token = super.beforeInvocation(fi);

		try {
			fi.getChain().doFilter(fi.getRequest(), fi.getResponse());
		} finally {
			super.afterInvocation(token, null);
		}

	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.springframework.security.access.intercept.AbstractSecurityInterceptor
	 * #getSecureObjectClass()
	 */
	@Override
	public Class<?> getSecureObjectClass() {
		// TODO Auto-generated method stub
		return FilterInvocation.class;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * org.springframework.security.access.intercept.AbstractSecurityInterceptor
	 * #obtainSecurityMetadataSource()
	 */
	@Override
	public SecurityMetadataSource obtainSecurityMetadataSource() {
		// TODO Auto-generated method stub
		return this.securityMetadataSource;
	}

	public void setSecurityMetadataSource(
			FilterInvocationSecurityMetadataSource securityMetadataSource) {
		this.securityMetadataSource = securityMetadataSource;
	}

	public void destroy() {

	}

	public void init(FilterConfig filterconfig) throws ServletException {

	}

}
